Wash the strawberries. Put a nice strawberry aside for decoration. Clean and dice the rest. Puree the strawberry cubes in a tall container and then stir in the chia seeds. Let it soak in the refrigerator overnight.
The next day, sweeten the strawberry and chia puree to taste and alternate with the yoghurt in a glass. Put the oatmeal on top as the top layer. Decorate with the retained strawberry.